JPH11114476A - Dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent dripping of a liquid, suppress contamination of the liquid with foreign substances, and discharge and drop the liquid in no pulsed state by forming a side route between the secondary side and the primary side of a filter by installing a check valve or an automatic switching valve. SOLUTION: A partitioning valve 10, a sucking back valve 12, and a filter 14 are installed in a pipe 8 in this order toward a nozzle 6 and a side route is formed between the secondary side and the primary side of the filter 14 while a check valve 16 or an automatic switching valve 16 is installed. At the time of discharging a coating liquid, the side route is closed and at the time of stopping discharge, the side route is opened to pass the following residual liquid by suction of the sucking back valve 12 and in the case the amount of foreign substances collected in the filter 14 is increased and the resistance of the flow route through the filter 14 is increased, the coating liquid is controlled to flow in the side route as to compensate the resistance increase. Consequently, dripping of the coating at the time of stopping discharge of the coating liquid is prevented and the production yield of products can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for coating a photoresist in a process of manufacturing a semiconductor or the like, and more particularly, to a dispenser (a coating liquid dropping device) for supplying a coating liquid onto a substrate.

[0002]

2. Description of the Related Art Conventionally, as a method of applying a photoresist or the like in a process of manufacturing a semiconductor or a color filter, a coating solution such as a photoresist is dropped onto a central portion of a substrate (wafer or glass plate) sucked by a vacuum chuck. A spin coating method (spin coating method) for forming a thin film by rotating a substrate at a high speed is generally known and used. This method utilizes the centrifugal force generated when a substrate such as a wafer rotates.
Although a thin film having a thickness of about 1 μm is formed, there are various matters to be considered in order to obtain a uniform desired film thickness. As one of them, there is a device for surely dropping the coating liquid such as photoresist onto the substrate.In this device, various valves and filters are installed in the piping from the coating liquid storage tank to the nozzle for discharging and dropping. There is a coating liquid dropping device (hereinafter referred to as a dispenser).

This dispenser discharges a coating liquid from a nozzle through, for example, a pipe from a coating liquid storage tank, and a gate valve for intermittently controlling the supplied coating liquid by opening and closing a flow path in the middle of the pipe. In order to prevent the coating liquid from dripping from the tip of the nozzle when the flow path is closed, a suck-back (suction) valve that draws the liquid level at the tip of the nozzle into the pipe and traps foreign matter and bubbles of the coating liquid. In general, a filter is provided to ensure that the above-mentioned dropping does not cause liquid dripping (dropping when it is not necessary to discharge) and that foreign matter such as gel or sludge is applied to the coating liquid. That is, the liquid is dropped in a state where the three major requirements, that is, the coating liquid is not included and that the coating liquid has no pulsation.

In the dispensers having the above three required performances, the performance differs depending on the arrangement order of the gate valves and the like. First, as shown in FIG. 6) There was a dispenser (1) arranged in the direction of the gate valve (10), the suck-back valve (12), and the filter (14) in the direction. In the dispenser (1) in this case, the coating liquid is discharged from the nozzle (6),
When the liquid is dropped on the substrate (4), the coating liquid flows in the order of the gate valve (10), the suck-back valve (12), the filter (14), and the nozzle (6). At the time, the sucking-back valve (12) sucks the coating liquid after the filter (14) (hereinafter referred to as a residual liquid) through the filter (14) into the pipe (8),
Liquid dripping from the tip of the nozzle (6) is prevented.

However, the dispenser of the above case (1)
With the increase in the amount of foreign matter trapped in the filter (14), suction of the following liquid remaining by the suck-back valve (12) is delayed, and the pressure in the suck-back valve (12) is reduced. However, there is a problem that air bubbles accumulate in the liquid crystal and the air bubbles cause dripping. Furthermore,
There was a problem that the life of the filter (14) was shortened due to the generation of the air bubbles.

As a second conventional example, as shown in FIG. 3, as shown in FIG. 3, a dispenser (1) provided in the order of a gate valve (10), a filter (14), and a suck-back valve (12) in the direction of a nozzle (6). was there.

However, the dispenser of this case (1)
Then, due to the stagnation of the coating liquid in the suck back valve (12) and the fluid friction caused by the operation of the suck back valve (12),
The coating liquid deteriorates and becomes a gel or sludge.
There is a problem that the product is more discharged and the coated product becomes defective.

Further, as a conventional example 3, as shown in FIG. 4, a dispenser (1) provided in the order of a filter (14), a gate valve (10), and a suck-back valve (12) in the direction of a nozzle (6). there were.

However, the dispenser of this case (1)
Then, similarly to the above-mentioned conventional example 2, there is stagnation of the application liquid in the suck-back valve (12) and generation of gel and sludge due to the operation of the suck-back valve (12).
Gel and sludge are generated due to the operation (0), and are discharged from the nozzle (6).

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art. It is an object of the present invention to provide a method for applying a predetermined amount of a coating solution such as a photoresist on a substrate of a semiconductor or a color filter. Dispenser for supplying and dropping is provided. A dispenser (1) is provided which does not drip (meaning that the liquid drops under discharging except for discharging), does not contain foreign matter in the liquid, and enables discharging and dropping without pulsation. .

[0011]

According to the present invention, there is provided a dispenser for discharging a coating solution from a nozzle through at least a gate valve, a suck-back valve, and a filter in order. And a dispenser characterized in that the secondary and primary sides of the filter are bypassed through a check valve or an automatic on-off valve.

[0012]

Embodiments of the present invention will be described below. As shown in FIG. 1, the dispenser according to the present invention discharges and drops a coating liquid from a coating liquid storage (not shown) through a pipe (8) and from a tip nozzle (6) onto a substrate (2). 1) and the piping (8)
, A gate valve (10), a suck-back valve (12), and a filter (14) are disposed in this order toward the nozzle (6), and the secondary and primary of the filter (14) are checked by a check valve (16) or It is configured to bypass the automatic on-off valve (16).

In the dispenser (1) as described above, the side path is closed when the application liquid is discharged, and the side path is opened when the discharge is stopped, so that the sac-back valve (12) sucks in the following liquid to pass the remaining liquid. It becomes something. By this suction, the following liquid remaining on the filter (14) flows through the bypass from the secondary side of the filter (14) to the primary side via the check valve (16) or the automatic opening / closing valve (16) and the filter (14). Some flow to the primary side through the filter, and when the amount of foreign matter collected in the filter (14) increases, the flow path resistance through the filter (14) increases. It starts to flow to the side road.

As described above, by forming a bypass between the secondary and the primary of the filter (14) through a check valve or an automatic opening / closing valve (16), especially when the discharge is stopped, that is, when the following liquid is sucked. In this case, the pressure reduction (negative pressure) in the suck-back valve (12) is reduced, and the foaming phenomenon of the coating liquid (photoresist or the like) and its deterioration phenomenon are reduced or prevented.

In the above description, the check valve or the automatic opening / closing valve (16) is used, which means that either a check valve or an automatic opening / closing valve may be used.

The check valve (16) used here includes:
For example, a lift check valve, a swing check valve, a ball check valve or a foot valve type may be mentioned, but a ball check valve is preferably used for the dispenser (1) of the present invention. As the automatic on-off valve (16), a general pneumatic ball valve type is used, and a suck-back valve (1) is used.
Opening and closing is automatically performed in conjunction with 2).

The gate valve (10) is not limited to that type, but may be, for example, a wedge gate valve,
Examples include a parallel slide valve and a double disc gate valve. Among them, the diaphragm type gate valve is preferably used from the viewpoint of low dust generation.

As the filter (14) of the dispenser (1), a 4.5 μm mesh polytetrafluoroethylene (PTFE) filter or the like is preferably used from the viewpoint of collection performance.

By using the dispenser (1) of the present invention having the above-described coating liquid circuit, a semiconductor wafer, which is a substrate (4) sucked by a vacuum chuck of a rotary coating machine (spinner), can be used. When a coating liquid such as a photoresist is dropped on a glass substrate for a color filter to obtain a desired thin film, no bubbles are generated in the suck-back valve (12). And can contribute to an improvement in product yield.

Further, the life (replacement time) of the filter (14) is extended, which contributes to cost reduction. By the way, as a result of the practical test, as shown in FIG.
In the dispenser (1), the filter (14) was replaced in 12 hours, but by using the dispenser (1) of the present invention as shown in FIG. 1, the filter (14) replacement time was reduced to 60 hours. Could be extended. That is, the downtime of the production line for replacing the filter (14) is reduced to 1/5 of the conventional one, which also contributes to an improvement in productivity.

Further, since stagnation in the suck-back valve (12) and fluid friction due to the valve operation are reduced, deterioration of the photoresist and the like and gel sludge, which does not cause foreign matters to enter, can be prevented. It can contribute to improving the yield of the product as a product.

As shown in FIG. 4, when the filter (14) is replaced, since the gate valve (10) is closed, air does not enter the pipe and air bubbles are easily removed, as compared with the conventional case (3). There is a merit that is.

As described above, the dispenser (1) of the present invention can be used for spin coating of a photoresist in a semiconductor manufacturing process, as well as for a pigment-dispersed photoresist or a transparent photoresist for dyeing in a color filter for a liquid crystal display. It can be used for spin coating such as a surface protective film.

[0024]

As described above, the present invention has the following effects. That is, the dispenser of the present invention, when spin-coating (spin-coating) a photoresist or the like in a manufacturing process of a semiconductor or the like, uses the coating liquid,
In at least a gate valve, a suckback valve, and a dispenser that discharges and drops onto a substrate such as a wafer from a nozzle at the tip through a filter in order, the secondary and primary of the filter are bypassed through a check valve or an automatic open / close valve. By using such a liquid circuit, no bubbles are generated in the suck-back valve, so that dripping when the discharge of the coating liquid is stopped is eliminated, which can contribute to an improvement in product yield. Also,
The service life (replacement time) of the filter is extended, which can contribute to cost reduction and reduction of filter replacement time.

Also, since the stagnation in the suck back valve and the fluid friction due to the valve operation are reduced, the deterioration of the photoresist and the like and the formation of gel sludge (contamination of foreign substances) are prevented, and the product yield is reduced. Can contribute to improvement.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing a dispenser according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing one embodiment of a conventional dispenser according to the present invention.

FIG. 3 is an explanatory view showing another embodiment of a conventional dispenser according to the present invention.

FIG. 4 is an explanatory view showing still another embodiment of the conventional dispenser according to the present invention.

[Explanation of symbols]

 1 ‥‥ Dispenser 4 ‥‥ Substrate 6 ‥‥ Nozzle 8 ‥‥ Piping 10 ‥‥ Seal valve 12 ‥‥ Suck back valve 14 ‥‥ Filter 16 ‥‥ Check valve or automatic open / close valve

Claims (1)

[Claims] 1. A dispenser for discharging a coating liquid from a nozzle through at least a gate valve, a suck-back valve, and a filter in order, wherein a secondary and a primary of the filter are bypassed through a check valve or an automatic on-off valve. A dispenser characterized by being made.